17.5: Nursing Care During the Final Hours of Life
Recognizing approaching death allows the patient, family members, and interdisciplinary team to prepare for the actively dying phase. The nurse has two primary responsibilities at this time: providing symptom management and preparing the family for what to expect as death is approaching. Nurses also have additional responsibilities regarding organ donation, postmortem care, and facilitating arrangements.
It is essential for nurses to ensure that patients and their family members have access to the interdisciplinary team in the final days before death. Developmentally appropriate education should be provided to the patient, family, and/or other caregivers about what to expect during the final hours of life, as well as immediately following the patient’s death. Early access to hospice support should be facilitated whenever possible to optimize care outcomes for the patient and the family. [1]
Nurses have a responsibility to carry out and respect the patient’s wishes to the extent they can. Each individual patient is different, and what works best for one patient might not work well for another. Dying is a multifaceted process that is unique to every patient. Providing a “good death” for patients means respecting their preferences and offering support for them and their family.
The nurse assumes multiple roles of advocate, professional caregiver, educator, and supporter and is frequently the one to facilitate a dignified death no matter the setting where death occurs. Nurses must be comfortable in “providing presence” and “bearing witness” with dying patients and their families. Rhythms of care (i.e., vital signs and routine assessments) often change during these final hours; be aware if these actions provide comfort or are burdens causing discomfort. [2]
Avoid overwhelming the family with too much medical jargon. Provide simple answers in accordance with the patient’s and family’s understanding and readiness for responses. Family members may be tired, emotional, and have difficulty concentrating. Because they may be in crisis and unable to retain much information, you may need to answer the same questions or provide the same information repeatedly. [3] It is helpful to provide family members written resources about what to expect. A commonly used resource in hospice care that can be very comforting for family members is Gone From My Sight: The Dying Experience . It is an inexpensive resource available to order online if it is not available at your facility.
There is no typical death. Each person dies in their own way, at their own time, with their own beliefs and values, and with unique relationships with family, friends, and significant others. Many people experience similar psychological and emotional responses during this time, such as fear of the dying process, fear of abandonment, fear of the unknown, nearing death awareness, and withdrawal. The nurse is essential in addressing patient’s fears and managing their symptoms according to their preferences.
Managing Common Symptoms During the Dying Process
Most patients experience the dying process as a natural slowing down of physical and mental processes. Two roads to death have often been described. One road involves sedation and lethargy leading to a comatose state and death. Another road involves confusion, restlessness, muscle jerks, seizures, and death. [4]
Pain and Dyspnea
During the final hours of life, changes in level of consciousness can make assessment and management of pain challenging. Consider behavioral cues such as grimacing and posturing, as well as previous pain issues. Some patients also demonstrate signs of increased dyspnea, commonly referred to as “air hunger,” with labored and increased work of breathing.
Pain pumps may be used to relieve severe pain, especially cancer-related pain. Medication can also be administered orally, even up to the last hours of life, for pain and dyspnea. [5] For example, Roxanol is a highly concentrated solution of morphine sulfate that can be administered sublingually for pain and/or air hunger. The typical dosage is 20 mg/mL. Morphine not only relieves pain, but also is used to relax respiratory muscles and improve air exchange to relieve air hunger. However, the nurse should always balance providing analgesia with the patient’s goal for maintaining alertness.
Principle of Double Effect
Nurses and family members may be hesitant to administer morphine in the last few hours of life, fearing that it may hasten death, yet also not wanting to see the patient suffer. The American Nurses Association and the Palliative Care Nurses Association support the nurse in this dilemma that is often referred to as the Rule of Double Effect . If the intent is good (i.e., relief of pain and suffering), then the act is morally justifiable even if it causes an unintended result of hastening death. Thus, the nurse should provide pain relief, without fear of sedation or respiratory depression that typically limits the administration of opioids, in the final days and hours of a patient’s life. [6]
Terminal Secretions
Terminal secretions, commonly known as the “death rattle,” can be a distressing and frightening symptom for family members and those involved in the patient’s care. Terminal secretions are usually observed 3-23 hours before death. Anticholinergic medications, such as atropine or scopolamine, can be used to dry the secretions. It is also helpful to reposition the patient on their side, if feasible. Suctioning is not recommended because it is not typically effective for these types of secretions and can cause increased agitation and distress in the patient. Family members caring for patients at home under hospice care should be warned about this phenomenon and instructed about potential treatment. [7]
View a supplementary video (11 minutes) on Lessons from a hospice nurse: Alia Indrawan at TEDxUbud . [8]
Phases of Dying
There are typically four phases that a person progresses through when dying. These phases include actively dying, transitioning, imminent death, and death.
Actively Dying
A patient in this phase will experience symptoms such as pain, dyspnea, fatigue, cough, incontinence, nausea and vomiting, depression, anxiety, and seizures. Treatments during this phase are focused on symptom management and emotional support to both the patient and the family. Read more about symptom management in the “ Palliative Care Management ” section of this chapter.
Educating the family and patient on what to expect is essential. Include written materials and progressive education as the patient’s condition changes. It is often helpful to provide guidance to the family in anticipation of upcoming phases of dying.
Transitioning
This is the phase between actively dying and imminent death where the patient withdraws physically. The patient begins to demonstrate decreased interest in activities of life with less frequent interactions with others and often has hallucinations. Other signs of this phase include hypoxia and acidosis. It is important for the nurse to keep the patient’s environment as comfortable as possible, such as keeping lights low and minimizing alarms and other noises.
Imminent
Death will occur at any point during the imminent phase due to multisystem organ failure. This phase usually occurs within 24 hours before death with common, recognizable signs. See Table 17.5 for typical signs that occur during this stage and indicate that death is imminent.
Table 17.5 Typical Signs as Death Becomes Imminent
| System | Signs |
|---|---|
| Cardiovascular | Cool, clammy skin; mottled extremities; rapid or irregular pulse |
| Musculoskeletal | Inability to ambulate, move, or turn in bed |
| Neurological | Confusion, restlessness, increased lethargy, hallucinations |
| Respiratory | Increased respiratory rate, inability to clear secretions, Cheyenne-Stokes respirations, noisy breathing (i.e., terminal secretions) |
| Urinary | Decreased or dark urine output |
During this stage, the family often requires additional support from the nurse as death becomes more of a reality. Vital signs are usually no longer assessed because they do not provide a benefit for the patient. The nurse should offer support by encouraging reminiscence, calming music, touch, light massage, presence, and prayer (according to family preferences) as the patient begins their transition.
The dying process is variable for each individual. Families often ask for a definitive time frame when death will occur. Although these signs that indicate progression within 24 hours, a specific time line cannot be predicted. Some patients seem to instinctively know when death will occur.
Be aware of religious practices and beliefs that are sacred to the patient and/or their family members at this time. Provide spiritual comfort through presence and prayer (based on patient preferences and the nurse’s comfort level). Call the agency chaplain and/or the patient’s clergy as indicted. (Read more about chaplains in the “ Spirituality ” chapter.) Encourage family members to bring in favorite hymns, scriptures, or symbols (i.e., a rosary) so the patient can experience these spiritual comforts through different senses (hearing, seeing, touching). [9]
Consider coaching family members about the five tasks that may serve as parting words with their loved one:
- To ask forgiveness
- To forgive
- To say “Thank you”
- To say “I love you”
- To say “Goodbye”
Read more about parting tasks in the book by Ira Byock, M.D. titled The Four Things That Matter Most. [10]
Death Vigil by Family Members
Family members have historically desired to be at the patient’s bedside during the days to hours before death. See Figure 17.27 [11] for artwork depicting the death vigil by family members when George Washington died.
Family members have common fears, such as the following:
- The patient being alone when they die
- Not knowing how to react or what to do
- Watching the patient suffer
- Not knowing if the patient has died
- Giving the “last dose” of medication at home and inadvertently causing death
It is important for the nurse to address family members’ fears proactively and provide education and support.
Death and Postmortem Care
Clinical death occurs when blood circulation ceases, the heart stops beating, and respirations stop. Within 4-6 minutes of clinical death, CPR can be performed to attempt resuscitation. However, because most patients receiving palliative or hospice care have Do Not Resuscitate (DNR) orders in place, CPR is not performed. After this time window, brain cells die from lack of oxygen, followed by death of cells in other organs. This is called biological death. Rigor mortis, stiffening of muscles, will begin to set in several hours following death and be at its peak 12-18 hours following death. Rigor mortis disappears 48 hours following death. The nurse should listen to the apical heartbeat for one full minute to ensure and document that death has occurred.
When a resident or patient passes away, the nurse should perform and document a final nursing assessment that includes the following:
- Date and time of the assessment
- Patient name
- Time of physician contact
- Individuals present at time of death (i.e., family members, friends)
- Lack of response to stimuli
- Absence of apical pulse
- Arrangement for transport to the morgue or funeral home
Care following a patient’s death requires sensitivity for the dignity of the deceased, as well as time for the care of family members. Following the death pronouncement, family members may feel numb and confused about what to do next. In a quiet and private place, explain the process for care of the body immediately following death. [12]
Following death, medical supplies and equipment tubes should be removed unless a coroner must approve of such measures. The goal is to provide a more personal closure experience for the family, leaving them memories of the deceased as a loved one rather than as a patient. Bathing, dressing, and positioning the body show respect and provide dignity for the patient and family. Position the body in proper alignment and place dentures in the mouth. Place dressings on leaking wounds and apply incontinence products as needed. Remember to honor cultural practices regarding care of the body after death and who should provide that care. [13]
The nurse should continue to provide support for the family and offer assistance as needed, such as contacting other family members to inform them of the death. Some family members may want to take pictures, comb their loved one’s hair, wash their face, hold their hand, kiss them, or crawl into bed and hold them. Support families in their various ways of saying goodbye.
Ask if the family completed preplanning for burial or cremation, but do not rush their final visit. In some cases, families will not have had time for making prearrangements. If they have made prearrangements, contact the funeral home. Be aware of county and agency policies that require notification of the local coroner prior to calling the funeral home. [14] When burial is chosen, the body will be embalmed, which is removing blood from the body and replacing it with an embalming solution that contains formaldehyde and other chemicals. The embalming process temporarily preserves the body to be shown at a funeral or memorial service. Cremation is the process of using heat to reduce the body to ashes that can be placed in a container called an urn. In some cultures, cremation is an ancient tradition. Depending on the family’s cultural beliefs and preferences, the ashes may be buried, placed in a mausoleum, or kept at home in an urn. See Figure 17.28 [15] for an image of a burial in a memorial garden.
In hospital settings, there may be a sense of urgency to get the room cleared as soon as possible so that another patient can be admitted. However, the nurse should advocate for the patient and make arrangements so the family does not feel rushed. [16] After the family has said their goodbyes and left the room, it is the nurses responsibility to ensure identification tags are applied to the body and the patient is moved to the morgue.
Organ Donation
If the patient is an organ or tissue donor, follow procedures as planned and in accordance with state and care setting guidelines, policies, and procedures. The patient’s drivers license may have information about their organ donation wishes. Federal law and Medicare regulations mandate that hospitals give surviving family members the chance to authorize donation of their loved one’s organs and tissues. Many family members feel consolation in helping others through organ donation despite their own loss. There is no cost for organ or tissue donation.
- American Association of Colleges of Nursing. (2021). End-of-life-care (ELNEC) . https://www.aacnnursing.org/ELNEC ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- TedX Talks. (2012, June 22). Lessons from a hospice nurse: Alia Indrawan at TEDxUbud . [Video]. YouTube. All rights reserved. https://youtu.be/2xs8qmk0OPc ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- https://irabyock.org/books/the-four-things-that-matter-most/ ↵
- “ Life_of_George_Washington_LCCN2002719381.jpg ” by Popular Graphic Arts is in the Public Domain ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵
- “ Memorial_Garden,_the_Museum_of_the_US_Air_Forces,_Dayton,_Ohio._(41410862864).jpg ” by Roland Turner is licensed under CC BY-SA 2.0 ↵
- This work is a derivative of Nursing Care at the End of Life by Lowey and is licensed under CC BY-NC-SA 4.0 ↵


15.24E: Brucellosis (Undulant Fever)
- Recognize the causes and symptoms of brucellosis
Brucellosis, also called Bang’s disease, Crimean fever, Gibraltar fever, Malta fever, Maltese fever, Mediterranean fever, rock fever, or undulant fever, is a highly-contagious zoonosis caused by ingestion of unsterilized milk or meat from infected animals or close contact with their secretions. Transmission from human to human, through sexual contact or from mother to child, is rare but possible.
Brucella spp . are small, gram-negative, non-motile, non-spore-forming, rod-shaped (coccobacilli) bacteria. They function as facultative intracellular parasites causing chronic disease, which usually persists for life. Symptoms include profuse sweating, and joint and muscle pain.
Species infecting domestic livestock are B. melitensis (goats and sheep), B. suis (pigs), B. abortus (cattle), B. ovis (sheep), and B. canis (dogs). B. abortus also infects bison and elk in North America and B. suis is endemic in caribou. Brucella species have also been isolated from several marine mammal species (pinnipeds and cetaceans).
Brucellosis in humans is usually associated with the consumption of unpasteurized milk and soft cheeses made from the milk of infected animals, primarily goats, infected with Brucella melitensis, as well as with occupational exposure of laboratory workers, veterinarians, and slaughterhouse workers. Some vaccines used in livestock, most notably B. abortus strain 19 , also cause disease in humans if accidentally injected.
Brucellosis induces inconstant fevers, sweating, weakness, anaemia, headaches, depression, and muscular and bodily pain. The symptoms are like those associated with many other febrile diseases, but with emphasis on muscular pain and sweating.
The duration of the disease can vary from a few weeks to many months or even years. In the first stage of the disease, septicemia occurs and leads to the classic triad of undulant fevers, sweating (often with characteristic smell, likened to wet hay), and migratory arthralgia and myalgia.
Antibiotics like tetracyclines, rifampicin, and the aminoglycosides streptomycin and gentamicin are effective against Brucella bacteria. However, the use of more than one antibiotic is needed for several weeks, because the bacteria incubate within cells.
Key Points
- Brucella can infect cattle, goats, dogs, and pigs. The bacteria can spread to humans by ingesting unsterilized milk or meat from infected animals, or close contact with their secretions.
- Brucellosis symptoms include fever, joint pain and fatigue. The infection can usually be treated successfully with antibiotics.
- People working in jobs where they often come in contact with animals or meat such as slaughterhouse workers, farmers, and veterinarians are at higher risk for contracting Brucellosis.
Key Terms
- brucellosis : Disease caused by the bacterium, Brucella, which is carried by ruminants. Symptoms include recurring fevers, sweating, weakness, anorexia, headaches, depression and generalized aches and pains.
- Brucella : A genus of Gram-negative bacteria. They are small, non-motile, non-encapsulated coccobacilli, which function as facultative intracellular parasites.


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According to Ash Maurya’s typology, Airbnb is an example of what type of business model?
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Direct
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Multisided
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Open
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Marketplace
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Which startup grew from a failed podcasting company called Odeo?
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Instagram
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Twitter
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StubHub
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Groupon
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What is the job to be done of a milkshake according to Christensen’s team’s customer observation research in the 'Link to Learning' video?
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Employ Chick-Fil-A cows
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Accompany on a long morning commute
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Placate children
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Satisfy hunger
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What is a change, typically minor, of the current business model in an attempt to capitalize on a closely related market opportunity?
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Innovation
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Disruption
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Iteration
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Increment
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A tool to identify your idealized target customer and develop a better understanding of his or her environment, behavior, concerns, and aspirations.
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Jobs to be done
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Business plan
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Business model canvas
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Empathy map
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A ________ is a formal document that typically describes the business and industry, market strategies, sales potential, and competitive analysis, as well as the company’s long-term goals and objectives.
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Business plan
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Business model
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Customer empathy map
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Revenue model
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Select the item that does not belong to the business model canvas.
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Market size
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Revenue streams
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Value proposition
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Customer segments
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The finished story benefit formula of [end customer wants] + [specific period of time] + [address objections] is designed for what component of the lean model canvas?
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Unfair advantage
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Unique value proposition
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Early adopters
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High concept pitch
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How does the social business model canvas differ from the business model canvas and lean model canvas?
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Is only used by nonprofit company
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Doesn’t have customer block and investment block
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Has profit block to talk about ways the company can makes more money
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Has impact measure, surplus, beneficiary segments, and social and customer value propositions
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Which of the following has the purpose of evaluating the team, the market for the concept, the financial viability, and possible pitfalls?
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Feasibility analysis
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Market analysis
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Financial analysis
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Management analysis
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Which of the following has the purpose of forecasting revenue and expenses, projecting a financial narrative, estimating project cost, and projecting cash flow?
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Feasibility analysis
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Market analysis
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Financial analysis
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Management analysis
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Which of the following identifies competitors and quantifies target customers and/or users in a specific industry?
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Feasibility analysis
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Market analysis
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Financial analysis
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Management analysis
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What assesses the prowess of the management and sufficiency of resources to bring the product or idea to market?
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Management analysis
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Operational feasibility analysis
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Financial analysis
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Cash flow
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What are expenses that do not vary with the level of sales, such as rent, salaries, utilities, insurance, and other operating expenses?
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Fixed costs
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Variable costs
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Balance sheet
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Cash flow statements
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Which of the following is a formal document that typically describes the business and industry, market strategies, sales potential, and competitive analysis, as well as the company’s long-term goals and objectives?
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Business plan
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Business model
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Customer empathy map
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Revenue model
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Which of these is not the purpose of a business plan?
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Thoroughly explain a business idea and how it will be carried out
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Planning tool and working plan over the course of several years
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Requirement to start a business
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Planning for “what-if” scenarios and explore new options
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Which of these components are not in a business plan?
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Business description
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Industry and market analysis
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Financial analysis
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None of these options is correct
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Estimated profits and expenses of the business is included in which of the following?
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Financial analysis
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Industry and market analysis
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Operation plan
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Marketing plan
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Who is best suited to write a business plan?
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Investor
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Founder(s)
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Consultant
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Chief financial officer


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active listening
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preparing to hear what another person is saying, receiving the sent message, and responding thoughtfully
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coalitions
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formalized groups of various team members who actively work together toward a common goal
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communication barriers
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circumstances that may impede the overall outcome or block progression of a plan
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community health education
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the process of providing information regarding optimal health and wellness at the community level
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community health needs assessment (CHNA)
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identifies strengths, resources, and current needs of a community
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cultural sensitivity
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an awareness of similarities and differences between cultures without making value judgments about those similarities and differences
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national campaigns
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a series of planned activities or marketing offerings intended to communicate information to the public on a national scale
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public service announcement (PSA)
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a message, video, or broadcast authorized by a government agency or nonprofit organization to provide information about an issue to the public
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TeamSTEPPS®
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an evidence-based set of teamwork tools aimed at optimizing client outcomes by improving communication and teamwork skills among health care professionals


7.2E: The Central Limit Theorem for Sample Means (Exercises)
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Use the following information to answer the next six exercises: Yoonie is a personnel manager in a large corporation. Each month she must review 16 of the employees. From past experience, she has found that the reviews take her approximately four hours each to do with a population standard deviation of 1.2 hours. Let \(X\) be the random variable representing the time it takes her to complete one review. Assume \(X\) is normally distributed. Let \(\bar{X}\) be the random variable representing the mean time to complete the 16 reviews. Assume that the 16 reviews represent a random set of reviews.
Example \(\PageIndex{1}\)
What is the mean, standard deviation, and sample size?
Answer
mean = 4 hours; standard deviation = 1.2 hours; sample size = 16
Exercise \(\PageIndex{2}\)
Complete the distributions.
- \(X \sim\) _____(_____,_____)
- \(\bar{X} \sim\) _____(_____,_____)
Example \(\PageIndex{3}\)
Find the probability that one review will take Yoonie from 3.5 to 4.25 hours. Sketch the graph, labeling and scaling the horizontal axis. Shade the region corresponding to the probability.
Figure \(\PageIndex{2}\).
2. \(P\)(________ \(< x <\) ________) = _______
Answer
- Check student's solution.
- 3.5, 4.25, 0.2441
Exercise \(\PageIndex{4}\)
Find the probability that the mean of a month’s reviews will take Yoonie from 3.5 to 4.25 hrs. Sketch the graph, labeling and scaling the horizontal axis. Shade the region corresponding to the probability.
Figure \(\PageIndex{3}\).
2. \(P\)(________________) = _______
Example \(\PageIndex{5}\)
What causes the probabilities in Exercise and Exercise to be different?
Answer
The fact that the two distributions are different accounts for the different probabilities.
Exercise \(\PageIndex{6}\)
Find the 95 th percentile for the mean time to complete one month's reviews. Sketch the graph.
Figure \(\PageIndex{4}\).
- The 95 th Percentile =____________


20.16: Shaking and Stirring Martinis
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Learning Objectives
- To test the difference between shaken and stirred martinis
Research conducted by
This is just made up data.
Case study prepared by
David Lane
Overview
This is an example to illustrate hypothesis testing and the binomial distribution. The statistician R. Fisher explained the concept of hypothesis testing with a story of a lady tasting tea. Here is an example based on James Bond who insisted that Martinis should be shaken rather than stirred. In this hypothetical experiment to determine whether Mr. Bond could tell the difference between a shaken and a stirred martini, we gave Mr. Bond a series of \(16\) taste tests. In each test, we flipped a fair coin to determine whether to stir or shake the martini. Then we presented the martini to Mr. Bond and asked him to decide whether it was shaken or stirred. Mr. Bond was correct on \(13/16\) trials.
Questions to Answer
Does Mr. Bond have the ability to tell the difference between a Martini that is shaken and one that is stirred?
Design Issues
This is only a made-up study.
Descriptions of Variables
| Variable | Description |
| Y | 0 = incorrect, 1 = correct |
Data Files
Martini.xls
Links
The Lady Tasting Tea
References
- Salsburg, D. (2002) The Lady Tasting Tea: How Statistics Revolutionized Science in the Twentieth Century. Owl Books


14.2B: Opportunistic Microorganisms
- Describe the traits of an opportunistic microorganism
In the general realm of biology, an opportunist is an organism that is able sustain its life from a number of different sources, but when favorable conditions arise, the organism immediately takes advantage of the opportunity to thrive. When the focus is turned more specifically to microbiology, scientists call organisms that behave this way opportunistic microorganisms. A microorganism is a microscopic organism that can either be a single cell, cell cluster, or multicellular. Microorganisms are very diverse and include bacteria, fungi, algae, and protozoa. Opportunistic microorganisms are typically non-pathogenic microorganisms that act as a pathogen in certain circumstances. They lay dormant for long periods of time until the hosts’ immune system is suppressed and then they seize the opportunity to attack.
Patients with Human Immunodeficiency Virus (HIV) are particularly susceptible to opportunistic infections. HIV can develop into Acquired Immune Deficiency Syndrome ( AIDS ), which infects and destroys helper T cells (specifically CD4+ T cells). When the number of CD4+ T cell numbers fall below a critical level, cell-mediated immunity is lost. When immunity is lost, the opportunistic microorganisms can easily infect the AIDS patient without being destroyed by the immune system. These opportunistic pathogens thrive while the human body slowly deteriorates.
An example of an opportunistic microorganism is Haemophilus ducreyi . This microorganism infects its host through broken skin or epidermis. In other words, without an open wound, this sexually transmitted disease would be unable to use the human body as a host. It takes advantage of the opportunity to infect the lymphocytes, macrophages and granulocytes as soon as it enters the area of broken skin.
Key Points
- A microorganism is a microscopic organism that can either be a single cell, cell cluster, or multicellular. Microorganisms are very diverse and include bacteria, fungi, algae, and protozoa.
- Opportunistic microorganisms are typically non-pathogenic microorganisms that act as a pathogen in certain circumstances. They lay dormant for long periods of time until the host ‘s immune system is suppressed and then they take that opportunity to attack.
- Haemophilus ducreyi, a microorganism, infects its host through broken skin or epidermis. Without the open wound, this sexually transmitted disease would be unable to use the human body as a host.
Key Terms
- microorganism : An organism that is too small to be seen by the unaided eye, especially a single-celled organism, such as a bacterium.
- Opportunistic : Taking advantage of situations that arise.
- immunodeficiency : A depletion in the body’s natural immune system, or in some component of it.


5.4: Enemies - Predation
At its simplest, we can consider predation (or herbivory) to be a function of predators (or herbivores) detecting, capturing, and consuming prey (or plant) individuals:
\[P\text{(predation)} = P\text{(detection)}\times P\text{(capture)} \times P\text{(consumption)}\]
where P() is the probability of each factor occurring. Consequently, predators/herbivores have many adaptations for increasing these terms and prey/plants have many adaptations for decreasing them. For example, predators may increase detection through enhanced senses, such as the exceptional eyesight of raptors, while prey may decrease detection through camouflage. Predators may increase capture through strategies like pack hunting in wolves, while prey may decrease capture through defensive armor or spines. Snakes are able to unhinge their jaws in order to increase the consumption of very large prey items, while some plant leaves contain compounds such as tannins that are very difficult to digest, decreasing herbivores’ consumption ability and deterring herbivory.
All of the adaptations described in the paragraph above result in trade-offs. Energy and other resources invested by prey in defensive structures or toxic compounds cannot then be put towards growth and reproduction. For predators, strategies such as pack hunting may increase the likelihood of successful capture, but also means that consumption is shared across numerous individuals.


1.2: Activities
Equipment
- \(8\frac{1}{2}\times 11\) sheets of paper with two dots
- a ruler
- a compass for drawing circles (not for telling which way is north)
- a steel marble
- carbon paper
- wood plank landing area
- nail target
The General Idea
Humans are not able to aim precisely. If someone aims at a specific pinpoint target, the results of their attempts to hit the target will produce a scatter pattern around the target. If there are two targets, and the human aims at one of them, it may or may not be possible to determine from the scatter pattern which target was the goal, depending upon the proximity of the two targets and the amount of spread of the scatter pattern.
In this lab, we will create these conditions in the following way:
- We are provided an \(8\frac{1}{2} \times 11\) piece of paper with two dots (targets) on it. Taping this paper to the cardboard landing area and inserting the nail into one of the dots to define the intended target gives us a region to record runs.
- Placing the carbon paper on top of the white paper gives us a means for recording the landing points of a steel marble dropped by a human aiming for the nail.
- After a number of drops, a scatter pattern is created on the white paper.
- After calculating the uncertainty in the scatter pattern, the spread from the average landing point can be computed mathematically, and then clearly delineated using the compass.
- The "spread circle" should immediately show whether the intended target can be determined, and if so, which one it was.
In an attempt to show how this procedure works for various degrees of uncertainty in the scatter pattern, you will do two separate experiments (use separate pieces of white paper for each) – one where the marble is dropped from a position above the head of the dropper, and one where the marble is dropped from waist-height. Important: It is possible for a human to hone their aim and improve their results with repeated trials, but we want every drop to be independent, so you should make sure that the dropper moves out of position after every drop, and starts fresh each time, giving them no way to make minute adjustments from the previous drop.
Data Analysis
[ As this is your first 9-series lab, much more guidance will be given regarding the methodology than is typical. Future labs will have similar sorts of steps for data analysis, but will not be so spelled-out for you. ]
For each of your two runs, do the following:
- Use the "average of averages" method outlined in Background Material to determine the average landing position of the marble. Multiple colors of ink will come in handy, to help you keep straight all the dots on the paper.
- Compute the standard deviation of the position from the average landing position, using the ruler to measure how far each data point is from the average. Creating a table like the one shown below will be helpful. Also, rounding the measurements of \(\Delta x\) to the nearest half-centimeter and using two significant figures for \(\Delta x^2\) should be plenty of precision.
- Use the compass and the ruler to draw a circle (probably best to use pencil) centered at the average landing position, with a radius equal to the uncertainty (standard deviation).
Hypothesis
In any other experiment, developing an hypothesis comes before the data collection and analysis. In this exercise we have placed it later, because the experiment doesn't test any actual physical principles, but has rather just been contrived to illustrate the concept of uncertainty. Whenever performing an experiment, the hypothesis outlines the expected results. In this experiment, since we are aiming at a specific point on the paper, the hypothesis is as simple as, "The person is dropping the marble on the target point on the paper." While no individual drop actually hits this target point, the hypothesis states what would happen if all of the uncertainty could be removed (i.e. if the person had perfect aim).
So how do we use our data to confirm the hypothesis? The short answer is that we check to see if the expected result lands within the uncertainty range of the experimental result (i.e. the average). In terms of what we have done here, the hypothesis is confirmed if the target point lies within the circle we have drawn around the average landing point.
But not so fast. The person may have actually been aiming at any number of points besides the target point – anywhere inside the circle, in fact. So it turns out that this hypothesis is too broad to be useful. A better hypothesis would be one that involves a comparison . This is why we have created two prospective targets, only one of which is the actual one, which we will call "Target A." Now we can form a more specific hypothesis: "Given that the person is aiming at one of the two targets, the target they are aiming at is A." Not all hypotheses can be boiled-down to two possibilities, but this is a nicely illustrative example. There are several possibilities here:
- only target A lies within the circle, confirming the hypothesis – It is important to understand that even with this confirmation, it doesn't prove beyond all doubt that the hypothesis is correct. It only confirms it to within our agreed-upon level of certainty.
- only target B lies within the circle, refuting the hypothesis – This would indicate that, to within uncertainty, the person was actually aiming at the other target.
- neither target lies within the circle – This result should lead us to reevaluate our starting point, where it was given that one of the two points was the target. Either that assumption was incorrect, or some mistakes were made in the experimental procedure or data analysis, or there was some unseen source of systematic error (e.g. a steady wind that blowing the marble horizontally during its journey).
- both targets lie within the circle – There are two possibilities for this result. First, it can be "fixed" by adding more trials, which will have the effect of moving the average landing point closer to the actual target (assuming no systematic errors), and farther from the alternative target, such that the latter then lands outside the uncertainty range. The second possibility is that the two targets are simply too close to each other for the degree of uncertainty we have. In this case, we say that the experiment "doesn't provide sufficient resolution" to confirm or refute the hypothesis.
Lab Report
Craft a lab report for these activities and analysis, making sure to include every contributing group member's name on the front page. You are strongly encouraged to refer back to the Read Me as you do this, to make sure that you are not leaving out anything important. You should also feel free to get feedback from your lab TA whenever you find that your group is at an impasse.
Every member of the group must upload a separate digital copy of the report to their lab assignment in Canvas prior to leaving the lab classroom . These reports are not to be written outside the lab setting.


One very productive way that new words are derived in English is by compounding, that is, combining two free morphemes to create a new word. Endocentric compounds have a head that determines the meaning and the category of the compound, and in English, the head is the second part of the compound.
A YouTube element has been excluded from this version of the text. You can view it online here: ecampusontario.pressbooks.pub/essentialsoflinguistics/?p=132
Check Yourself
1. In the sentence, “The room contained a bearskin rug,” what kind of compound is
bearskin
?
2. In the sentence, “Randy worked as a cowhand on the ranch,” what kind of compound is
cowhand
?
3. In the sentence, “Hyunji manages a bookshop,”, what kind of compound is
bookshop
?
Answers
Video Script
We’ve seen that English frequently uses affixation to derive new words. Affixation is quite
productive
, meaning that our mental grammar uses the process for many different words, even for new words that come into the language. You’ve probably generated new words yourself sometimes by adding affixes to existing words.
Another extremely productive derivational process in English is
compounding
. Compounding is different from affixation. In affixation, a bound morpheme is affixed to a base. Compounding derives a new word by joining two morphemes that would each usually be free morphemes.
For example, if I take the free morpheme
green
, an adjective, and combine it with the free morpheme
house
, a noun, I get the new word
greenhouse
. We can tell that this is a new word because its meaning is different from what we would get if we just combined the two words to make a phrase. We could walk down the street describing houses: This is a brown house and this one here is a tall house and here is a red house and here is a greenhouse. But a greenhouse is something different from a house that’s green! It’s a new word, derived by compounding.
Credit: Joe Shlabotnik on Flickr; Attribution 2.0 Generic (CC BY 2.0)
Image “Greenhouse at Wilson Farm, East Lexington MA“ by John Phelan is licensed under CC BY 3.0.
Another way that words derived by compounding differ from words derived by affixation is that a compound word doesn’t really have a base or root that determines the meaning of the word. Instead, both pieces of a compound make a sizeable contribution to the meaning. For example,
yoga pants
are pants that you wear to do yoga, and
emerald green
is the particular colour of green that emeralds are. So it doesn’t make sense to say that compounds have a root.
On the other hand, there is one part of a compound that has a special role, which we can see if we think about the categories of the words that make up a compound. If you look at these examples,
dry clean
stir fry
outrun
power wash
Each compound is made up of a different category of the word on the left plus a verb on the right. But in each case, the compound word is a verb. Even if both parts of a compound contribute to the meaning of the compound, it’s the
head
of a compound that determines its category. We say that English is a
head-final
language because in English the second part of the compound determines the category of the compound. Some languages are
head-initial
, with the head as the first element in a compound.
In many compounds, the head determines the category and also constrains the meaning of the compound. So
dog food
is a kind of food, not a kind of dog, and
yoga pants
are a kind of pants, not a variety of yoga. Compounds like this, where the meaning relationship between the head and the whole compound is obvious, are called
endocentric
. But in some compounds, the meaning relationship is not so transparent. For example, a
redhead
is a person, not a kind of head; a
nest egg
is money that you’ve saved, not a kind of egg; a
workout
is not a particular kind of out, and
facebook
is not a book at all! Compounds where the meaning of the head does not predict the meaning of the compound are said to be
exocentric
.


42.6: Describing Distributions on Histograms
Lesson
Let's describe distributions displayed in histograms.
Exercise \(\PageIndex{1}\): Which One Doesn't Belong: Histograms
Which histogram does not belong? Be prepared to explain your reasoning.
Exercise \(\PageIndex{2}\): Sorting Histograms
- Your teacher will give your group a set of histogram cards. Sort them into two piles—one for histograms that are approximately symmetrical, and another for those that are not.
-
Discuss your sorting decisions with another group. Do both groups agree which cards should go in each pile? If not, discuss the reasons behind the differences and see if you can reach agreement. Record your final decisions.
- Histograms that are approximately symmetrical:
- Histograms that are not approximately symmetrical:
-
Histograms are also described by how many major peaks they have. Histogram A is an example of a distribution with a single peak that is not symmetrical.
Which other histograms have this feature? -
Some histograms have a gap, a space between two bars where there are no data points. For example, if some students in a class have 7 or more siblings, but the rest of the students have 0, 1, or 2 siblings, the histogram for this data set would show gaps between the bars because no students have 3, 4, 5, or 6 siblings.
Which histograms do you think show one or more gaps? -
Sometimes there are a few data points in a data set that are far from the center. Histogram A is an example of a distribution with this feature.
Which other histograms have this feature?
Exercise \(\PageIndex{3}\): Getting to School
Your teacher will provide you with some data that your class collected the other day.
- Use the data to draw a histogram that shows your class’s travel times.
- Describe the distribution of travel times. Comment on the center and spread of the data, as well as the shape and features.
- Use the data on methods of travel to draw a bar graph. Include labels for the horizontal axis.
- Describe what you learned about your class’s methods of transportation to school. Comment on any patterns you noticed.
- Compare the histogram and the bar graph that you drew. How are they the same? How are they different?
Are you ready for more?
Use one of these suggestions (or make up your own). Research data to create a histogram. Then, describe the distribution.
- Heights of 30 athletes from multiple sports
- Heights of 30 athletes from the same sport
- High temperatures for each day of the last month in a city you would like to visit
- Prices for all the menu items at a local restaurant
Summary
We can describe the shape and features of the distribution shown on a histogram. Here are two distributions with very different shapes and features.
- Histogram A is very symmetrical and has a peak near 21. Histogram B is not symmetrical and has two peaks, one near 11 and one near 25.
- Histogram B has two clusters. A cluster forms when many data points are near a particular value (or a neighborhood of values) on a number line.
- Histogram B also has a gap between 20 and 22. A gap shows a location with no data values.
Here is a bar graph showing the breeds of 30 dogs and a histogram for their weights.
Bar graphs and histograms may seem alike, but they are very different.
- Bar graphs represent categorical data. Histograms represent numerical data.
- Bar graphs have spaces between the bars. Histograms show a space between bars only when no data values fall between the bars.
- Bars in a bar graph can be in any order. Histograms must be in numerical order.
- In a bar graph, the number of bars depends on the number of categories. In a histogram, we choose how many bars to use.
Glossary Entries
Definition: Center
The center of a set of numerical data is a value in the middle of the distribution. It represents a typical value for the data set.
For example, the center of this distribution of cat weights is between 4.5 and 5 kilograms.
Definition: Distribution
The distribution tells how many times each value occurs in a data set. For example, in the data set blue, blue, green, blue, orange, the distribution is 3 blues, 1 green, and 1 orange.
Here is a dot plot that shows the distribution for the data set 6, 10, 7, 35, 7, 36, 32, 10, 7, 35.
Definition: Frequency
The frequency of a data value is how many times it occurs in the data set.
For example, there were 20 dogs in a park. The table shows the frequency of each color.
| color | frequency |
|---|---|
| white | \(4\) |
| brown | \(7\) |
| black | \(3\) |
| multi-color | \(6\) |
Definition: Histogram
A histogram is a way to represent data on a number line. Data values are grouped by ranges. The height of the bar shows how many data values are in that group.
This histogram shows there were 10 people who earned 2 or 3 tickets. We can't tell how many of them earned 2 tickets or how many earned 3. Each bar includes the left-end value but not the right-end value. (There were 5 people who earned 0 or 1 tickets and 13 people who earned 6 or 7 tickets.)
Definition: Spread
The spread of a set of numerical data tells how far apart the values are.
For example, the dot plots show that the travel times for students in South Africa are more spread out than for New Zealand.
Practice
Exercise \(\PageIndex{4}\)
The histogram summarizes the data on the body lengths of 143 wild bears. Describe the distribution of body lengths. Be sure to comment on shape, center, and spread.
Exercise \(\PageIndex{5}\)
Which data set is more likely to produce a histogram with a symmetric distribution? Explain your reasoning.
- Data on the number of seconds on a track of music in a pop album.
- Data on the number of seconds spent talking on the phone yesterday by everyone in the school.
Exercise \(\PageIndex{6}\)
Evaluate the expression \(4x^{3}\) for each value of \(x\).
- \(1\)
- \(2\)
- \(\frac{1}{2}\)
(From Unit 6.3.4)
Exercise \(\PageIndex{7}\)
Decide if each data set might produce one or more gaps when represented by a histogram. For each data set that you think might produce gaps, briefly describe or give an example of how the values in the data set might do so.
- The ages of students in a sixth-grade class.
- The ages of people in an elementary school.
- The ages of people eating in a family restaurant.
- The ages of people who watch football.
- The ages of runners in a marathon.
Exercise \(\PageIndex{8}\)
Jada drank 12 ounces of water from her bottle. This is 60% of the water the bottle holds.
- Write an equation to represent this situation. Explain the meaning of any variables you use.
- How much water does the bottle hold?
(From Unit 6.2.2)


6.9: Assignment- Reports
At some point in your career, you might find yourself sitting on a committee or leading one. Meeting minutes are a great way to practice report writing since the structure is always linear, meaning the minutes are based on the order in which the events of th meeting unfolded.
Meeting minutes may seem to be insignificant but they are actually official documents of the company and can be subpoenaed as evidence in a court of law. It’s important to take careful minutes.
For this assignment, you will watch a video of a mock meeting in the “Watch It” box below. Then create a Word document as the meeting minutes. As you watch the video, focus on applying what you learned about reports to create minutes that summarize essential points. Your meeting minutes should be understandable by another reader months or perhaps even years after the meeting.
You will submit this assignment as a Word attachment to your instructor via email.
Required Information of Meeting Minutes
- Date
- Time of the meeting
- Name of attendees
- Acceptance or corrections to previous meeting minutes
- Actions to be taken including the next steps
- The person assigned to each action
- Checkpoint on tasks/progress
- The voting outcomes (if there are any)
This meeting meeting took place on January 28th, 2016, at 3pm EST.
The participant’s names are Sarah, Eleanor, and Julie.
Click here to read a transcript of this video.
Assignment Resources
Do you need additional help with this assignment? Here are some resources:
- Watch this video (or read the transcript): 5 Minutes on Taking Minutes
-
Examples of meeting minutes:
- Wikimedia Foundation Minutes
- Adoption of Minutes; interviews: discussion
- OSI Board Meeting Minutes, April 11, 2007
Grading Rubric
| Criteria | Not Evident | Developing | Proficient | Exemplary | Points |
|---|---|---|---|---|---|
| Organization and format |
2 pts
Writing lacks logical organization. It may show some coherence but ideas lack unity. Serious errors and generally is an unorganized format and information. |
3 pts
Writing is coherent and logically organized, using a format suitable for the material presented. Some points may be contextually misplaced and/or stray from the topic. Transitions may be evident but not used throughout the essay. Organization and format used may detract from understanding the material presented. |
4 pts
Writing is coherent and logically organized, using a format suitable for the material presented. Transitions between ideas and paragraphs create coherence. Overall unity of ideas is supported by the format and organization of the material presented. |
5 pts
Writing shows high degree of attention to details and presentation of points. Format used enhances understanding of material presented. Unity clearly leads the reader to the writer’s conclusion and the format and information could be used independently. |
5 pts |
| Content |
2 pts
Some but not all required questions are addressed. Content and/or terminology is not properly used or referenced. Little or no original thought is present in the writing. Concepts presented are merely restated from the source, or ideas presented do not follow the logic and reasoning presented throughout the writing. |
3 pts
All required questions are addressed but may not be addressed with thoughtful consideration and/or may not reflect proper use of content terminology or additional original thought. Additional concepts may not be present and/or may not be properly cited sources. |
4 pts
All required questions are addressed with thoughtful consideration reflecting both proper use of content terminology and additional original thought. Some additional concepts may be presented from other properly cited sources, or originated by the author following logic and reasoning they’ve clearly presented throughout the writing. |
5 pts
All required questions are addressed with thoughtful in-depth consideration reflecting both proper use of content terminology and additional original thought. Additional concepts are clearly presented from properly cited sources, or originated by the author following logic and reasoning they’ve clearly presented throughout the writing. |
5 pts |
| Development – Critical Thinking |
4 pts
Shows some thinking and reasoning but most ideas are underdeveloped, unoriginal, and/or do not address the questions asked. Conclusions drawn may be unsupported, illogical or merely the author’s opinion with no supporting evidence presented. |
6 pts
Content indicates thinking and reasoning applied with original thought on a few ideas, but may repeat information provided and/ or does not address all of the questions asked. The author presents no original ideas, or ideas do not follow clear logic and reasoning. The evidence presented may not support conclusions drawn. |
8 pts
Content indicates original thinking, cohesive conclusions, and developed ideas with sufficient and firm evidence. Clearly addresses all of the questions or requirements asked. The evidence presented supports conclusions drawn. |
10 pts
Content indicates synthesis of ideas, in-depth analysis and evidence beyond the questions or requirements asked. Original thought supports the topic, and is clearly a well-constructed response to the questions asked. The evidence presented makes a compelling case for any conclusions drawn. |
10 pts |
| Grammar, Mechanics, Style |
2 pts
Writing contains many spelling, punctuation, and grammatical errors, making it difficult for the reader to follow ideas clearly. There may be sentence fragments and run-ons. The style of writing, tone, and use of rhetorical devices disrupts the content. Additional information may be presented but in an unsuitable style, detracting from its understanding. |
3 pts
Some spelling, punctuation, and grammatical errors are present, interrupting the reader from following the ideas presented clearly. There may be sentence fragments and run-ons. The style of writing, tone, and use of rhetorical devices may detract from the content. Additional information may be presented, but in a style of writing that does not support understanding of the content. |
4 pts
Writing is free of most spelling, punctuation, and grammatical errors, allowing the reader to follow ideas clearly. There are no sentence fragments and run-ons. The style of writing, tone, and use of rhetorical devices enhance the content. Additional information is presented in a cohesive style that supports understanding of the content. |
5 pts
Writing is free of all spelling, punctuation, and grammatical errors and written in a style that enhances the reader’s ability to follow ideas clearly. There are no sentence fragments and run-ons. The style of writing, tone, and use of rhetorical devices enhance the content. Additional information is presented to encourage and enhance understanding of the content. |
5 pts |
| Total: | 25 pts |
Contributors and Attributions
- Assignment: Reports. Provided by : Lumen Learning. License : CC BY: Attribution
- Mock Meeting for Minute Taking. Authored by : learn4lifewithmrsb. Provided by : YouTube. Located at : https://www.youtube.com/watch?v=ItIpCy7o0L4 . License : CC BY: Attribution
- 5 minutes on Taking Minutes. Authored by : Lianza. Provided by : Lianza. Located at : lianza.org.nz/5-minutes-taking-minutes. License : CC BY: Attribution


<IP_ADDRESS>: Reproductive Isolation
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Learning Objectives
- Explain how reproductive isolation can result in speciation
Reproductive Isolation
Given enough time, the genetic and phenotypic divergence between populations will affect characters that influence reproduction: if individuals of the two populations were to be brought together, mating would be improbable, but if mating did occur, offspring would be non-viable or infertile. Many types of diverging characters may affect reproductive isolation, the ability to interbreed, of the two populations. Reproductive isolation is a collection of mechanisms, behaviors, and physiological processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced is not fertile.
Scientists classify reproductive isolation in two groups: prezygotic barriers and postzygotic barriers. Recall that a zygote is a fertilized egg: the first cell of the development of an organism that reproduces sexually. Therefore, a prezygotic barrier is a mechanism that blocks reproduction from taking place; this includes barriers that prevent fertilization when organisms attempt reproduction. A postzygotic barrier occurs after zygote formation; this includes organisms that don’t survive the embryonic stage and those that are born sterile.
Some types of prezygotic barriers prevent reproduction entirely. Many organisms only reproduce at certain times of the year, often just annually. Differences in breeding schedules, called temporal isolation, can act as a form of reproductive isolation. For example, two species of frogs inhabit the same area, but one reproduces from January to March, whereas the other reproduces from March to May.
In some cases, populations of a species move to a new habitat and take up residence in a place that no longer overlaps with other populations of the same species; this is called habitat isolation. Reproduction with the parent species ceases and a new group exists that is now reproductively and genetically independent. For example, a cricket population that was divided after a flood could no longer interact with each other. Over time, the forces of natural selection, mutation, and genetic drift will likely result in the divergence of the two groups.
Behavioral isolation occurs when the presence or absence of a specific behavior prevents reproduction from taking place. For example, male fireflies use specific light patterns to attract females. Various species display their lights differently; if a male of one species tried to attract the female of another, she would not recognize the light pattern and would not mate with the male.
Other prezygotic barriers work when differences in their gamete cells prevent fertilization from taking place; this is called a gametic barrier. Similarly, in some cases, closely-related organisms try to mate, but their reproductive structures simply do not fit together. For example, damselfly males of different species have differently-shaped reproductive organs. If one species tries to mate with the female of another, their body parts simply do not fit together..
In plants, certain structures aimed to attract one type of pollinator simultaneously prevent a different pollinator from accessing the pollen. The tunnel through which an animal must access nectar can vary in length and diameter, which prevents the plant from being cross-pollinated with a different species.
When fertilization takes place and a zygote forms, postzygotic barriers can prevent reproduction. Hybrid individuals in many cases cannot form normally in the womb and simply do not survive past the embryonic stages; this is called hybrid inviability. In another postzygotic situation, reproduction leads to the birth and growth of a hybrid that is sterile and unable to reproduce offspring of their own; this is called hybrid sterility.
Key Points
- Reproductive isolation can be either prezygotic (barriers that prevent fertilization ) or postzygotic (barriers that occur after zygote formation such as organisms that die as embryos or those that are born sterile).
- Some species may be prevented from mating with each other by the incompatibility of their anatomical mating structures, or a resulting offspring may be prevented by the incompatibility of their gametes.
- Postzygotic barriers include the creation of hybrid individuals that do not survive past the embryonic stages ( hybrid inviability ) or the creation of a hybrid that is sterile and unable to produce offspring ( hybrid sterility ).
- Temporal isolation can result in species that are physically similar and may even live in the same habitat, but if their breeding schedules do not overlap then interbreeding will never occur.
- Behavioral isolation, in which the behaviors involved in mating are so unique as to prevent mating, is a prezygotic barrier that can cause two otherwise-compatible species to be uninterested in mating with each other.
- Behavioral isolation, in which the behaviors involved in mating are so unique as to prevent mating, is a prezygotic barrier that can cause two otherwise compatible species to be uninterested in mating with each other.
Key Terms
- reproductive isolation : a collection of mechanisms, behaviors, and physiological processes that prevent two different species that mate from producing offspring, or which ensure that any offspring produced is not fertile
- temporal isolation : factors that prevent potentially fertile individuals from meeting that reproductively isolate the members of distinct species
- behavioral isolation : the presence or absence of a specific behavior that prevents reproduction between two species from taking place
- prezygotic barrier : a mechanism that blocks reproduction from taking place by preventing fertilization
- postzygotic barrier : a mechanism that blocks reproduction after fertilization and zygote formation
- hybrid inviability : a situation in which a mating between two individuals creates a hybrid that does not survive past the embryonic stages
- hybrid sterility : a situation in which a mating between two individuals creates a hybrid that is sterile


5.1: Gender Socialization
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 In this chapter, we’ll be exploring how language and the media often reinforce or exacerbate the gap in the United States. For example, one could ask, “What are gender differences?” But consider for a moment the question, “What differences does gender make?” While the questions might seem very similar to one another, the first question is evoking a description of the concept of gender , while the second question is evoking an exploratory descriptive of inequality resulting from gender construction.


1: Lab 1- Anatomical Language
This is a lab manual for a college-level human anatomy course. Mastery of anatomy requires a fair amount of memorization and recall skills. The activities in this manual encourage students to engage with new vocabulary in many ways, including grouping key terms, matching terms to structures, recalling definitions, and written exercises. Most of the activities in this manual utilize anatomical models, and several dissections of animal tissues and histological examinations are also included. Each unit includes both pre- and post-lab questions and six lab exercises designed for a classroom where students move from station to station. The vocabulary terms used in each unit are listed at the end of the manual and serve as a checklist for practicals.


8.3: Fronts
Fronts are boundaries between contrasting masses of air. Atmospheric scientists recognize fronts of different spatial scales. These range from the quasi-stationary fronts along which cyclones form to "weather" fronts embedded in cyclones. Fronts are three-dimensional features. They are not only a boundary between contrasting air masses running along the surface, but extend upwards into the troposphere as we will later learn.
Quasi-stationary fronts
At the global scale are quasi-stationary fronts found migrating within a particular latitudinal zone throughout most of the year. The polar front is the boundary between polar-type air and tropical-type air. The polar front migrates between about 35 o and 65 o , following the annual cycle of earth surface heating (Figure \(\PageIndex{1}\)). Above the polar front is found the polar front jet stream, a high velocity corridor of wind that controls the development and movement of mid-latitude cyclones.
During the winter, the polar front slides equatorward along with invading cold air. During the summer, the polar front retreats northward. This seasonal migratory pattern moves cyclones into and out of the middle latitudes giving them quite variable weather conditions over the seasons.
Synoptic Scale Fronts
At a smaller or synoptic scale are the "weather" fronts e.g., cold, warm, occluded, and stationary. Cold fronts are those where cold air replaces warm air. A warm front is where warm air replaces cold air. A noticeable difference between warm and cold fronts is the slope of the front above the surface. The frontal surface, the portion extending upward above the surface, is much steeper for the cold front than warm front. The steepness of the frontal surface directly impacts the type of weather one experiences along these fronts.
An occluded front forms when a cold front catches up with a warm front. Air is often converging at a front producing a trough of low pressure along it. A decrease in pressure is often experienced with their passage. A stationary front is where no change in air masses or movement of the front occurs. The weather associated with these fronts is discussed later.
Weather Map Depiction
Meteorologists use both symbols and color to distinguish between synoptic scale fronts on weather maps. If printed in color, warm fronts are shown as a line of red semi-circles pointing in the direction of movement. Cold fronts are depicted as a line of blue triangles. Occluded fronts appear in purple with both warm and cold front symbols on the same side. The symbols point in the direction of the front is moving. Stationary fronts are alternating warm and cold front symbols on opposite sides, indicating no movement. A portion of a simplified weather map is shown in Figure \(\PageIndex{5}\). The map depicts a wave cyclone as it is starting to occlude. We see an occluded front trailing southeast from the center branching into cold and warm fronts.
The location of air masses on weather maps are identified by their letter abbreviation, e.g., mT, cP, mP. Shading is used to show where areas of precipitation occur. Looking at the local environmental setting can give a clue as to what mechanism caused uplift for precipitation to form. Note that the areas of precipitation in Figure \(\PageIndex{5}\) either occur ahead of a front (frontal lifting) or to the north of the center of the low (convergent lifting).
The distribution of air pressure is shown by isobars, lines connecting points of equal air pressure. Isobars are drawn in increments of 4 millibars on surface weather maps. Recall that it is the pressure gradient that controls wind speed. Strong pressure gradients and hence faster winds occur where the isobars are closely spaced. Weak pressure gradients and slow winds occur where the isobars are widely spaced.


3.4: How?
As stated above, there are many careers related to working with children and families. Since many of you will look into teaching at some point in your early childhood career, let us take a closer look at how that might happen.
As you hone many of the interpersonal traits and dispositions needed, you will also be taking classes to complete the formal education necessary to meet program requirements. This link will take you to our department website where you are able to find more information specific to your early childhood studies here at Chabot College, including your needed coursework and valuable academic information.
Professional Pathways
The field of Early Childhood Education has multiple pathways for those who are interested in directly or indirectly working with children and families. This section will explore the education needed to become an early childhood professional, career options, and continuation of education and professional development.
Education
There are many entrance points along the career path in Early Childhood Education. The following pathways are to be used for those who are seeking employment in the State of California. Each state has different requirements and since this text originated in California, we will speak specifically for our students and our state.
Child Development Associate Credential (CDA)
While the CDA has been around for 45 years, this is most recognized in states that do not have comprehensive higher education systems in Child Development or Early Childhood Education. Here is some key information taken directly from the CDA website:
- The CDA is based on a core set of competency standards, which guide early care professionals as they work toward becoming qualified teachers of young children.
- The Council works to ensure that the nationally transferable CDA is a credible and valid credential, recognized by the profession as a vital part of professional development.
- CDAs have knowledge of how to put the CDA Competency Standards into practice and understanding of why those standards help children move with success from one developmental stage to another. CDAs know how to nurture the emotional, physical, intellectual, and social development of children. [34]
For those who hold a CDA Credential, in California, it can be used in the following ways in California:
- Earn your California Child Development Associate Teacher Permit (see permit matrix option 2 under Associate Teacher)
- You can use them as transferable units to a higher education program of study to continue with the additional units you would need to work in a state-funded early education center
Associates Degree for Transfer (ADT) in Early Childhood Education and/or Certificates of Achievement
The California Community College System, to which Chabot College belongs, offers several options in the Early Childhood course of study. At Chabot, you can earn an associate’s (AA) degree, which requires that you complete 31 specific units of ECD along with the general education requirements of an associate’s degree.
You can also earn a transfer degree (AS-T) in Early Childhood Education, which requires 24 units of ECD along with general education requirements that meet the transfer requirements of the California State University system. With the AS-T degree, you will be accepted at a California State University and you would enter as a junior (provided that you are continuing your education in either Child Development or a related field).
We also offer an AA degree in Early Childhood Intervention.
You also can earn one or more of the certificates of specialization that we currently offer for our students. Currently, those certificates include specializations in:
- Associate and Basic Teacher certificates that align with requirements for the California Child Development Permit
- Infant-Toddler Specialist
- Intervention Assistant
- Curriculum Specialist/Transitional Kindergarten
- Early Childhood Administration
- Educational Aide
- Family Child Care/Entrepreneurship
For help with your ECD plan, you should meet with our Professional Development Coordinator. She is here to help you plan your ECD classes so you meet your career goals while working towards the degree or certificate you want. It is also importnat to make an appointment with a counselor to ensure that you are taking the right general education courses as well.
Our course of study at College of the Canyons:
- ECD 50 Early Childhood Principles and Practices (this is the class you are currently enrolled in)
- ECD 56 Child Growth and Development
- ECD 62 Child, Family, and Community
- ECD 63 Early Childhood Curriculum
- ECD 69 Child Study: Observation and Assessment
- ECD 54 Child Health, Safety, and Nutrition
- ECD 79 Teaching in a Diverse Society
- ECD 90 Practicum – Supervised Field Experience
And for the AA degree:
- ECD 60 Introduction to the Young Child with Exceptional Needs
- ECD 95 Work Experience
- ECD 96 Work Experience Seminar
The following courses require prior coursework that must be completed with a passing grade before enrollment (called pre-requisites):
- ECD 69 Child Study: Observation and Assessment requires ECD 56
- ECD 63 Early Childhood Curriculum requires ECD 50 and ECD 56
- ECD 90 Practicum – Supervised Field Experience requires ECD 50, ECD 56, ECD 62 and ECD 63
- ECD 60 ECD 60 Introduction to the Young Child with Exceptional Needs requires ECD 56
- ECD 95/96 must be take at the same time
We provide this information so you can plan your schedule accordingly should you want to complete your degree in 2 years.
Bachelor’s Degree
Several institutions of Higher Education offer Bachelor’s degrees for those pursuing a career in working with children. In-state, those institutions can be California State Universities (CSU’s), University of California (UC’s), or private institutions. One of the best ways to choose an institution is to find one that meets your financial needs and the needs you have as a student to be successful.
Master’s Degree
As indicated above, the same is true for Master’s Degrees. Again, it is best to find an institution that will work best for you and your career goals.
Doctoral Degree
Fewer higher education institutions offer doctoral degrees in Child Development/Early Childhood Education. However, in the state of California, a group of higher education faculty is currently working with institutions to offer this degree. We know from this study - Transforming the Workforce 0 – 8 , that the more knowledge a practitioner has about how children grow and develop, the more prepared that practitioner is to provide high quality environments that are supportive and responsive to the needs of children and their families.
Child Development Permit
In response to the implementation of state-subsidized preschool, California developed a permit structure that details what the personnel at each level are authorized to do and the education and experience requirements for those levels. The current six‐level permit structure is based upon a career ladder approach with each level increasing in coursework preparation and commensurate authorization or responsibility. Please see the next page for the Permit Matrix. Most coursework is completed by candidates at community colleges. [35]
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New Teacher Comments When I started my first ECE class I thought I would get my degree, get a job, and be done. Now I know that was just the start. To be a good teacher is to be a lifelong learner. Don’t be afraid to join organizations and go to workshops and conferences. I was petrified to go to my first one, but it was so much fun. I learned a lot that I could instantly take back to my classroom and met so many new and helpful people. Find a more seasoned teacher or someone you feel comfortable with. You will have many questions and need a sounding board. Later, when you know more, you can ‘pay it forward’ with another new teacher. |
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Pause to Reflect What will help you as you begin your journey into the world of Early Childhood Education? What advice might you have for others as they begin their own journey? |
This page was edited and revised by Alice Hale (Chabot College) using the Libretexts remixing tool.